In fact, the last time this scenario presented itself, Barça came out on top in a 2-0 victory over Inter in game which saw the return of Samuel Eto’o to Camp Nou. Pep Guardiola was the Barça manager at the time and Barça, in a must-win situation after having won only one of its three group stage matches heading into the Inter clash, were forced to tackle the pivotal duel without their superstar.

But Gerard Piqué put Barça ahead in the 10th minute of play, and Pedro Rodríguez doubled the lead in the 26th, giving the blaugranes all the goals they’d need to pick up the three points.

Now, while that may have been the only Inter match Messi would miss, until now, there have been plenty of other clashes between the European giants over the last six decades:

1987 Mundialito de Clubs in Milan 23/6/87 Inter 3 Barça 1 (Hughes)The last of four editions of an unofficial summer tournament played in Italy in the eighties. Barça finished fourth in the five-team group, Inter third and AC Milan were winners.

2002-03 Champions League 2nd group stage 18/2/03 Barça 3 (Saviola, Cocu, Kluivert) Inter 0 26/2/03 Inter 0 Barça 0Barça topped the group without losing a match and Inter qualified in second place. Barça then lost to Juventus in the quarter finals, and Inter went out to AC Milan in the semi-finals (on away goals despite the fact that they both play in the same stadium!)

2009–10 Champions League Group F 16/9/09 Inter 0 Barça 0 24/11/09 Barça 2 (Piqué, Pedro) Inter 0Barça topped the group with 11 points and Inter qualified in second place with 9. Barça went on to beat Stuttgart and Arsenal, while Inter beat Chelsea and CSKA Moscow and the two team met again the semi-finals of the same competition.

2009–10 Champions League Semi-Finals 20/4/10 Inter 3 Barça 1 (Pedro) 28/4/10 Barça 1 (Piqué) Inter 0Inter won 3-2 on aggregate and went on to win the title for the first time in 45 years, beating Bayern Munich in the final.